AGPtek Speed Training Resistance Parachute - Small (40" Size), 15 lbs of resistance, Fit up to a 42" waist 40" diameter, Also available in Medium (48") and Large (56") 15 lbs of resistance Fits all sizes (up to a 42" waist), Quick Release for overspeed training. Fully functional unit includes parachute and belt. IMPORTANT NOTE: This 40" Size is more suitable for long-distance running. For short sprints, we suggest 56" Size version. If the Resistance is not meet you need. Please feel free to contact us. We respond email in 1- 24 business hours.